Here's what he told the Sun, apparently some time ago, which has the Internet itching today:
"I'll never really accept it, and I always, in the back of my head, think, 'What if I could get the old gang back together?'Last year, of course, was the tenth anniversary of Firefly's debut on television and all the key players got together for a celebratory panel at San Diego Comic-Con International. Many fans suspected, or at least hoped, that there might be news of a continuation or reboot at the convention, but it wasn't to be.
"Well, you know, it's something I would love to do. When I made Serenity, I said here's one thing I'll never do again -- a movie based on something that some people know about and some people don't, with tons of characters who all know each other and who you have to introduce.
"And then my second movie was The Avengers.
"Part of me is like, 'God, it would be great when I finish Avengers 2 to do that [but] I suspect very strongly that after Avengers 2 the next thing I do will be a one-man show. Possibly one monkey."